1100 Am J Health-Syst Pharm—Vol 70 Jul 1, 2013 Letters L etters The Letters column is a forum for rapid exchange of ideas among readers of AJHP. Liberal criteria are ap- plied in the review of submissions to encourage contribu- tions to this column. The Letters column includes the following types of contributions: (1) comments, addenda, and minor updates on previously published work, (2) alerts on potential problems in practice, (3) observations or comments on trends in drug use, (4) opinions on apparent trends or contro- versies in drug therapy or clinical research, (5) opinions on public health issues of interest to pharmacists in health systems, (6) comments on ASHP activities, and (7) human interest items about life as a pharmacist. Reports of adverse drug reactions must present a reasonably clear description of causality. Short papers on practice innovations and other original work are included in the Notes section rather than in Letters. Letters commenting on an AJHP article must be received within three months of the article’s publication. Letters should be submitted electronically through http://ajhp.msubmit.net. The following conditions must be adhered to: (1) the body of the letter must be no longer than two typewritten pages, (2) the use of references and tables should be minimized, (3) the number of authors should be no more than three, and (4) the entire letter (including references, tables, and authors’ names) must be typed double-spaced. After acceptance of a letter, the authors are required to sign an exclusive publication state- ment and a copyright transferal form. All letters are subject to revision by the editors. Effect of environmental conditions on performance of elastomeric pumps W ith the advent of ambulatory infu- sion devices, home-based chemo- therapy services are feasible for both adult and pediatric populations. Home chemotherapy not only reduces the cost of treatment, it also optimizes the phar- macy services and improves patients’ quality of life. 1,2 Studies have shown that home chemotherapy is safe, effective, and well received by patients and carers. 3 The success of home chemotherapy, when delivered by elastomeric pumps, depends on the accuracy and reliability of the devices. Departures from expected infusion times could result in scheduling discrepancies for home health services as well as the outpatient clinic department and may contribute to a less-effective treatment or a greater risk of adverse effects. 4 The potential for infusion dis- crepancies is illustrated by the study of Remerand et al., 5 who reported that elastomeric pumps correctly connected to catheters for the administration of re- gional anesthesia began infusions late or failed to deliver infusions at all in 20.5% of 430 cases. They also reported that in vivo flow rates differed from in vitro rates in 40% of the cases. Deviations from the expected infu- sion time can be related to the viscosity and quality of life of patients with colorec- tal cancer receiving home chemotherapy or outpatient treatment: a randomised controlled trial. BMJ. 2001; 322:826. 4. Thiveaud D, Demazieres V, Lafont J. Com- parison of the performance of four elas- tomeric devices. Eur J Hosp Pharm. 2005; 11:54-6. 5. Remerand F, Vuitton AS, Palud M et al. Elastomeric pump reliability in postop- erative regional anesthesia: a survey of 430 consecutive devices. Anesth Analg. 2008; 107:2079-84. 6. Wang J, Moeller A, Ding YS. Effects of atmospheric pressure conditions on flow rate of an elastomeric infusion pump. Am J Health-Syst Pharm. 2012; 69:587-91. Dahlia Salman, B.Sc., M.Sc., Ph.D. Researcher in Oncology Pharmacy Practice and Pharmaceutical Analysis k0709683@kingston.ac.uk Stephen Barton, B.Sc., Ph.D., CSci, CChem, MRSC, Principal Lecturer Shereen Nabhani-Gebara, Pharm.D., BCOP, Senior Lecturer School of Pharmacy and Chemistry Kingston University London Kingston Upon Thames United Kingdom KT1 2EE The authors have declared no potential conflicts of interest. DOI 10.2146/ajhp130150 W e agree that multiple factors affect the flow from an elastomeric pump. These include head height, ambient temperature, and solution viscosity, and these factors are additive. The guide for of the infusion solution and to environ- mental conditions. Thus, we read with interest the article by Wang et al. 6 about the effects of atmospheric conditions on the performance of an elastomeric pump. Their study addressed important issues, such as pump performance under hyperbaric and hypobaric conditions. It is important to note, however, that tem- perature may also affect pump perfor- mance and can fluctuate considerably depending on the outside climate, use of air conditioning, and patients’ activities, such as bathing and sleeping. The tem- peratures to which a pump is exposed in clinical practice may differ from the con- stant one used in the study of Wang et al. (31 °C). Future studies of elastomeric pumps should investigate how variations in more than one external condition influ- ence pump performance. 1. Lüthi F, Fucina N, Divorne N et al. Home care—a safe and attractive alternative to inpatient administration of intensive chemotherapies. Support Care Cancer. 2012; 20:575-81. 2. Lowenthal RM, Piaszczyk A, Arthur GE et al. Home chemotherapy for cancer patients: cost analysis and safety. 1996; 165:184-7. 3. Borras JM, Sanchez-Hernandez A, Navarro M et al. Compliance, satisfaction,